CLN: read_html global importing check (#51505)

Author: mroeschke

pandas/io/html.py

@@ -53,33 +53,6 @@
 if TYPE_CHECKING:
  from pandas import DataFrame
 
-_IMPORTS = False
-_HAS_BS4 = False
-_HAS_LXML = False
-_HAS_HTML5LIB = False
-
-
-def _importers() -> None:
- # import things we need
- # but make this done on a first use basis
-
- global _IMPORTS
- if _IMPORTS:
- return
-
- global _HAS_BS4, _HAS_LXML, _HAS_HTML5LIB
- bs4 = import_optional_dependency("bs4", errors="ignore")
- _HAS_BS4 = bs4 is not None
-
- lxml = import_optional_dependency("lxml.etree", errors="ignore")
- _HAS_LXML = lxml is not None
-
- html5lib = import_optional_dependency("html5lib", errors="ignore")
- _HAS_HTML5LIB = html5lib is not None
-
- _IMPORTS = True
-
-
 #############
 # READ HTML #
 #############
@@ -922,16 +895,10 @@ def _parser_dispatch(flavor: str | None) -> type[_HtmlFrameParser]:
  )
 
  if flavor in ("bs4", "html5lib"):
- if not _HAS_HTML5LIB:
- raise ImportError("html5lib not found, please install it")
- if not _HAS_BS4:
- raise ImportError("BeautifulSoup4 (bs4) not found, please install it")
- # Although we call this above, we want to raise here right before use.
- bs4 = import_optional_dependency("bs4") # noqa:F841
-
+ import_optional_dependency("html5lib")
+ import_optional_dependency("bs4")
  else:
- if not _HAS_LXML:
- raise ImportError("lxml not found, please install it")
+ import_optional_dependency("lxml.etree")
  return _valid_parsers[flavor]
 
 
@@ -1194,8 +1161,6 @@ def read_html(
  See the :ref:`read_html documentation in the IO section of the docs
  <io.read_html>` for some examples of reading in HTML tables.
  """
- _importers()
-
  # Type check here. We don't want to parse only to fail because of an
  # invalid value of an integer skiprows.
  if isinstance(skiprows, numbers.Integral) and skiprows < 0:

pandas/tests/io/test_html.py

@@ -1,5 +1,4 @@
 from functools import partial
-from importlib import reload
 from io import (
  BytesIO,
  StringIO,
@@ -26,6 +25,7 @@
  Timestamp,
  date_range,
  read_csv,
+ read_html,
  to_datetime,
 )
 import pandas._testing as tm
@@ -36,7 +36,6 @@
 
 from pandas.io.common import file_path_to_url
 import pandas.io.html
-from pandas.io.html import read_html
 
 
 @pytest.fixture(
@@ -1350,9 +1349,6 @@ def run(self):
  else:
  self.err = None
 
- # force import check by reinitalising global vars in html.py
- reload(pandas.io.html)
-
  filename = datapath("io", "data", "html", "valid_markup.html")
  helper_thread1 = ErrorThread(target=self.read_html, args=(filename,))
  helper_thread2 = ErrorThread(target=self.read_html, args=(filename,))